Introduction: Filtration media selection is dependent upon filtration level required and operational pressures. Traditionally, the filter portion is formed from woven wire mesh manufactured from drawn wire, arranged in a grid pattern although different weaves are available, allowing different levels of filtration using different wire diameters. The open area of the filter is limited by the wire diameters, affecting the overall strength of the woven mesh. The design freedoms of additive manufacturing (AM) allows filter media design with known aperture sizes whilst reducing equivalent wire diameter to produce filter media with a greater open area compared to the equivalent woven wire mesh.
Method: AM filter media were designed to have aperture sizes of 500µm and 1000µm as found in #32 and #18 mesh respectively, but with a decrease in ‘wire’ diameter to increase the ratio of open area. Strength was increased through addition of further filtration layers to form depth filters. The filter media were then tested for aperture size, collapse pressure and pressure drop.
Results: AM filter media designs delivered an increase in open area compared to comparable woven wire mesh media. Addition of further layers increased the filters strength and the complexity of the particulate path through the filter and so decreased the path size.
Conclusions: Filter media designs produced using AM can be manipulated to produce an increase in open area, retaining strength compared to conventional woven wire mesh. The increased open area decreases the pressure drop across the filter and so less pumping energy is required.